tomb1269

Let me start by saying I am aware that fuel milage topic has been beaten in death. However, I see all these post for guys getting 18, 19 , 20 mpg. Now I assume this these to be pure highway numbers. I just picked up a 2005 FX4 SCrew from my dad with 82000 miles on it. It has been very well maitained by local Ford dealer (I believe plugs are original). It is all stock, with a hard Tonnaue cover. I live in the Albany NY area and commute 4 / 5 miles (10 minutes) each way to work. I have been getting 9 to 10 mpg in town and a mixed highway (back county road= 55 - 60 MPH / Interstate = 72 -75 MPH) 60% / city 40% mileage of 13 - 14 mpg. It has not been extremely cold here. The engine seems to be running great. It still has the power to turn the 18 inch 265/65 tires from a stand still on dry pavement. I am not hard on the throttle on a day to day basis, but I will put it to the wall when needed. I am also under the impression that these engines are sensitive to running tempature with respect to MPGs, and that my short commute does not help at all. BUT WHAT am I missing, I expected to be down around 11-13 town and 15 to 17 highway. I just wish I could get there........
Any ideas would be apprecaited......... FYI, I am not interested in aftermarket add-ons (CAI, CHIPS, etc) as it is my impression the results are mixed at best.

Mod (Ret.)

Read the posts that you refered to as "beaten to death". They contain tips on what can be done to help your mileage. It's there. You'll just have to search and read.

sargeek1975

If you're only traveling 4-5 miles you're screwed.

The numbers you're putting up seem pretty acurate..........

eej711

the 4X4 and FX4 trucks get right around that so what you are getting is accurate. The cheapest way to get a tiny bit better is keep RPMs under 2000 and do the gotts mod but you will stay right around what you already got.

BassAckwards

Nobody gets 20mpg with the 5.4 unless it's 2wd, weighs nothing, has a 3.15 rear end, and they built there house next to the interstate.

Your getting what should be expected of an FX4. A 2wd MIGHT see 18 and that's really good.

Olysouthpaw24

2004 5.4 3v 3.73LS 4x4
175,000 miles
Full synthetic 10w-30
265/70/17 AT tires

12.5 is worst city tank I have had
14 is typical city tank
15.5-16.5 typical mixed tank
17.2-18 typical highway tank

18.7 = best tank ever

I drive very light-footed and live in CA where all fuel is tainted with ethanol. These are all hand calculated no BS numbers.

BassAckwards

Those are impressive Highway numbers!

I've been able to average between 14.75-15.5 City driving by messing with my TC lock ups with my Edge with a best tank of 16.03mpg

but on highway driving ~72 I can only get around 15-16. I can get 17-18 if I slow down to 60 but then everyone honks at me

Olysouthpaw24

Haha ya.... i tend to drive near 60....65 is what I try to top out at.... except when the wife is in the car, then we have to do 70-75 and my mpg drops to ~16 as well. Especially w/ 3.73 gears these trucks are sensitive to speed.

I tried a tank doing 51-55 and I still only got 17.5. It seems 60-63 is the sweet spot.

sargeek1975

You're misinformed........

I have a 2004 5.4L FX4 SCAB........and when I drive from Va Beach to Jersy I have gotten up to 24mpg average; not just instant readings. As soon as I hit the hills up there it goes back down to 18.........


With flat highways, keeping the cruise on and doing around 62mph I have gotten over 20mpg numerous times.



EDIT:
I've made it from Va Beach to Springfield Ma.......a 503 mile trip; with a 1/4 tank of gas left in my 35 gallon tank. If that helps you guys out at all in believing me. (503/26=19.3.........average over the entire trip, including all the damn hills)

BassAckwards

I'm not talking about 62mph I'm talking Highway speeds of at least 70 mph. Big difference in MPG between 60 and 70.

However I highly doubt you averaged 24mpg on a "highway speed" trip with a 4x4. You got 50% better than the EPA estimate if that is true. Maybe if you were going 40 becasue I can lock my TC at 35mph and going 40 down my county road I do 1000rpm and can average 22mpg. So if you have stock tires and a 3.15 rear end, I might belive 24 @50-55mph or something.

Edit: Just saw your picture. 19 is very impressive for highway speeds over that distance, I can believe that although it's on the high end, but very possible as you obviously prove. What's your setup? Tires, intake, tuner etc?